Manufactured using Intel’s industry-leading 22nm technology with 3-D Tri-Gate transistors, each coprocessor features more cores, more threads, and wider vector execution units than an Intel Xeon processor. The high degree of parallelism compensates for the lower speed of each core to deliver higher aggregate performance for highly parallel workloads.

When do I use Intel Xeon processors and Intel Xeon Phi coprocessors?

Think "resuse" rather than "recode"

Since languages, tools, and applications are compatible for both Intel Xeon processor and Intel Xeon Phi coprocessors, now you can think “reuse” rather than “recode”.

Single programming model for all your code. The Intel Xeon Phi coprocessor gives developers a hardware design point optimized for extreme parallelism, without requiring them to re-architect or rewrite their code. No need to rethink the entire problem or learn a new programming model; simply recompile and optimize existing code using familiar tools, libraries, and runtimes.

Performance multiplier. By maintaining a single source code between Intel Xeon processors and Intel Xeon Phi coprocessors, developers optimize once for parallelism but maximize performance on both processor and coprocessor.

Execution flexibility. Designed from the ground up for high-performance computing. Unlike a GPU, a coprocessor can host an operating system, be fully IP addressable, and support standards such as Message Passing Interface (MPI). Additionally, it can operate in multiple execution modes:

"Symmetric" mode: Workload tasks are shared between the host processor and coprocessor

"Native" mode: Workload resides entirely on the coprocessor, and essentially acts as a separate compute nodes

"Offload" mode: Workload resides on the host processor, and parts of the workload are sent out to the coprocessor as needed. NOTE: GPUs can ONLY be run in mode and often sits idle.